Additional treatment for esophageal cancer patients with incomplete resection due to the surrounding organ invasion: a nationwide survey of 45 Japanese centers

Background: We occasionally experience incomplete resection of esophageal cancer due to the surrounding organ invasion. The efficacy of additional treatment in these cases is unknown. Methods: We studied 445 patients with esophageal squamous cell carcinoma who were unable to undergo curative esophagectomy due to cancer invasion to the surrounding organs at 45 esophageal centers in Japan. Survival outcomes were compared based on the additional treatment modalities. Results: Postoperatively, 175 (40.0%) received no additional treatment, while 59 (13.5%), 153 (35.0%), and 50 (11.4%) received additional chemotherapy, chemoradiotherapy, or radiotherapy, respectively. The three-year disease progression and overall survival rates were 90.6% (95% confidence interval 87.2–93.1%) and 15.4% (95% confidence interval 12.2–19.3%), respectively. Multivariable analysis revealed that chemotherapy, chemoradiotherapy, and radiotherapy were all independently associated with reduced disease progression (hazard ratios [95% confidence intervals]: 0.57 [0.40–0.81], 0.52 [0.39–0.69], and 0.48 [0.33–0.72], respectively). Meanwhile, additional treatment with chemotherapeutic agents (chemotherapy and chemoradiotherapy) was independently associated with better overall survival (hazard ratios [95% confidence intervals]: 0.51 [0.35–0.73] and 0.59 [0.44–0.79], respectively); however, radiotherapy alone had a limited impact (hazard ratio [95% confidence interval]: 0.74 [0.50–1.10]). Conclusions: Any additional treatment could suppress disease progression after incomplete resection, but radiotherapy alone has a limited effect. Additional systemic chemotherapeutics may increase patient survival.